ABSTRACT The Veterans Millennium Health Care and Benefits Act (Millennium Act) of 1999 mandated the Department of Veterans Affairs (VA) to provide non-institutional long-term care to veterans. Adult Day Health Care (ADHC) is a key component of that spectrum of long-term care services, providing health maintenance, rehabilitation services and socialization in a group setting during daytime hours. Previous studies have demonstrated that sleep disruption is associated with poor functional outcomes among older adults. While we have found high rates of sleep disturbance among ADHC patients, it is not addressed within routine clinical care, and treatment is typically limited to medications. Nonpharmacological interventions have been shown to be effective in improving sleep and are associated with improvements in mood, quality of life and health among older adults. The aims of the proposed study are to evaluate whether a non-pharmacological Sleep Intervention Program (SIP), delivered in the context of adult day health care (ADHC), will lead to significant improvements in self-reported and objectively-measured (by wrist actigraphy) sleep quality and to evaluate whether treatment-related improvements are maintained at 6-months follow-up. A total of 70 veterans over age 60 who have been participating in a VA ADHC program for at least one month will be included. Individuals will be excluded if they: 1) show evidence of severe untreated sleep disordered breathing necessitating immediate referral for treatment (>30 respiratory events per hour of recording, based on at-home overnight respiratory monitoring), 2) do not meet diagnostic criteria for an insomnia disorder, or 3) have a Mini-Mental State Examination score <20 suggesting moderate-to-severe cognitive impairment that would limit comprehension of the intervention. The intervention will involve a 4-session manualized cognitive-behavioral therapy for insomnia (CBT-I), plus daily time outdoors to increase exposure to bright light. This SIP will be compared to an information-only control condition using a randomized, controlled trial with 70 veterans (35 per group). All participants will complete baseline, post-treatment and 6-month follow-up assessments of self-reported (questionnaire) and objectively-measured (wrist actigraphy) sleep. Study hypotheses will be tested with 2 (group) x3 (time) mixed model Analysis of Variance. To our knowledge, this study would be the first to address the unmet need for non-pharmacological treatment of sleep problems among ADHC patients. The intervention design (e.g., use of a manualized treatment that can be provided by non-psychologists) will facilitate translation into routine care and application in other similar VA programs. PUBLIC HEALTH RELEVANCE: PROJECT NARRATIVE The proposed work is directly relevant to the VA's focus on high-quality non-institutional long-term care for older veterans. Adult Day Health Care (ADHC) is a key component within the spectrum of non-institutional long-term care services offered by VA. This study will address a key health concern, poor sleep quality, in the context of VA ADHC. Since sleep disturbance has repeatedly been shown to contribute to poor health outcomes, and pharmacological treatments may increase risk of falls and other adverse consequences, evaluating nonpharmacological interventions shown to be effective in other settings has great promise. Findings from this study can inform ongoing re-organization of VA long-term care services, and enhance the quality and outcomes of VA ADHC programs.